Knitting system for circular knitting machines



KNITTING SYSTEM FOR CIRCULAR KNITTING MACHINES Filed April 27, 1964 March 1967 P. A. MAHLER ETAL 4 Sheets-Sheet l INVENTORS. PETER A. MAHLER KERWIN R. BOYER ATTYS.

March 28, 1967 P. A. MAHLER ETAL 3,310,963

KNITTING SYSTEM FOR CIRCULAR KNITTING MACHINES Filed April 27, 1964 4 Sheets-Sheet 2 FIG- 3.

Match 1967 P. A. MAHLER ETAL 3,310,963

\ KNITTING SYSTEM FOR CIRCULAR KNITTING MACHINES Filed April 27, 1964 4 Sheets-Sheet 5 7J6 77 45} 72 75 74 BJ TI I GM 2 KNITTING SYSTEM FOR CIRCULAR KNITTING MACHINES 4 Sheets-Sheet 4 Filed April 27, 1964 m ul United States Patent "ice 3,310,963 KNITTING SYSTEM FGR CIRCULAR KNITTING MACHINES Peter A. Mahler and Kerwin R. Boyer, High Point, N.C., assignors to The Singer Company, New York, N.Y., a corporation of New York Filed Apr. 27, 1964, Ser. No. 363,025 11 Claims. (Cl. 66-50) The present invention relates to circular knitting machines, and more particularly to improved knitting systerns for controlling the needles thereof to produce varied stitch forms.

The character of the stitch form produced on a needle at a knitting station is determined by the elevation of the needle as it enters the yarn feed station to take yarn. The fundamental stitch forms for producing a plain knitted tube, for use as the stocking blank for example, are obtained by cams operating directly on the needles through the conventional needle butts. Contoured heel and toe pouches are formed by reciprocating the needle cylinder and inactivating selected needles by elevating them above the conventional needle cams under the control of picks and earns operating on the needle butts or stitches operating on the jack butts. Reinforcing yarns may be inserted by controlling the elevation of the needles by the jacks. In order to produce a pattern in the tube, the elevation of the needles is controlled by individual selector jacks associated with the needles and having a plurality of butt levels which determine the production of patterns by the presence or absence of a butt at selected levels on a particular jack. The jack is displaced by the engagement of a butt thereon with a jack actuator in the form of a slide or cam controlled from a pattern selection drum or other patterning mechanism which is conventionally common to all of the actuators, or at least a major portion of them.

The present invention provides an improved knitting system for circular knitting machines of the type used for knitting ladies hosiery and the like, wherein the selector jacks are displaced vertically in the needle cylinder by the jack actuators, and which enables full utilization of the length of the selector jacks to provide the desired pattern selectivity.

More specifically, the knitting system of the present invention employs selector slides operable upon the selector jacks to provide different elevations of the needles independently of the needle cams so as to enable inclusion of needle cams for performing all of the common stitch formations within the limited circumferential length of the needle cam track.

More specifically, the present invention provides a cam track for lifter jacks intermediate the needles 'and selector jacks which cooperates with the slides for the selector jacks and the cams and slides for the needles to effect the desired elevation of the needles in a fully effective and efficient manner.

In particular, the present invention provides in the cam track for the intermediate lifter jacks, a plurality of cams of differing heights which, in turn, provide correspondingly different elevations of the needles.

Another object of the present invention is to provide in a plural feed knitting machine having slides operable on the selector jacks in advance of one station, improved means for repeating the selection made at the first station at the next station, said repeated selection being effected by the selector jacks themselves.

The invention also provides an improved structural arrangement for the knitting head embracing the dial, the yarn guide ring, the feed stations, and the upper end of the needle cylinder so as to provide ready access for 33%,963 Patented Mar. 28, 1967 adjustment and maintenance of the proper setting for the knitting system.

The present invention provides a knitting machine which is highly versatile with respect to the patterns which may be knit thereon, thereby reducing substantially the down-time which is normally required for changes in pattern.

All of the objects of the present invention are more fully set forth hereinafter with reference to the accompanying drawings wherein:

FIG. 1 is 'a view in side elevation of the upper portion of a circular knitting machine embodying the present invention, with certain mechanism omitted for the purpose of illustration;

FIG. 2 is a view in front elevation of a portion of the machine, as seen from the line 22 in FIG. 1, certain parts of the machine being hidden by cover members;

FIG. 3 is an enlarged fragmentary transverse sectional View taken on the line 33 of FIG. 1, with certain mechanism omitted;

FIG. 4 is a cam development showing the cams and slides operative on the needle butts and the jack butts, as seen from the interior of the cylinder, showing in front elevation the feed stations with needles thereat, and showing other needles and their associated jacks in side elevation; and

FIG. 5 is a diagram of the butt arrangement for the needles, lifter jacks, and selector jacks in the needle cylinder, as seen from the outside of the cylinder.

Referring now to FIG. 1, the knitting machine illustrated therein comprises a frame 20 having at its upper end a needle cylinder 21 rotatably mounted therein. A yarn guide ring 22, pivotally secured to the frame at 24, surrounds the upper end of the cylinder. A rotary dial shown in part at 71 in FIG. 3 overlies the open upper end of the needle cylinder 21 for simultaneous rotation with the needle cylinder through dial superstructure 23 mounted on the frame through a pivotal yoke 29. The dial is covered by a stationary dial cap 70 (see FIG. 3) which mounts the usual dial cams, yarn trimmer, and yarn control elements (not shown) including a yarn-end suction takeoff which is connected to the suction side of a blower in the lower part of the frame 2% through a suction duct 25 including a yarn-end collector or trap 26.

As shown in FIG. 3, the knitting machine embodies two feed stations, a main feed station at 72 and an auxiliary feed station at 73. The main feed station comprises a throat plate 74 and a plurality of yarn feed fingers 75 pivotally mounted on the guide ring 22 as indicated at 75a and 75b. Yarn finger actuators 76 are mounted on the frame 20 to operate the feed fingers 75. At the auxiliary feed, a throat plate 77 and yarn feed fingers 78 are carried by the yarn guide ring 22 and feed finger actuating mechanism 79 (shown in FIG. 3) is mounted on the frame 20. The knitting yarns are fed to the knitting stations 72 and 73 from yarn packages 27 mounted on suitable creels or package supports 28 at the rear of the upper foot portion of the frame 2%.

In accordance with a feature of the invention, the dial cap 70, the dial 71, and the dial superstructure 23 may be pivoted upwardly about the pivotal yoke 29 to enable visual inspection of the needle cylinder with the yarn feed stations 72 and 73 intact. The yarn guide ring 22 may also be elevated on its pivot 24 to raise the feed fingers and throat plates of the stations 72 and 73 out of the way so that the needles and the upper end of the cylinder may be inspected and serviced. Since the yarn guide ring 22 is mounted on a separate pivot 24 from the dial structure pivot at 29, with the yarn guide ring structure elevated, the dial structure may be pivoted back into place and the relationship between the needles and the dial structure may be inspected and checked without interference from the yarn guide ring 22 and the mechanism carried thereby. Inasmuch as the pivotal axes of the yarn and guide ring respectively are angularly spaced about the needle cylinder 21, wide and easy access to the various parts of the dial structure is possible, greatly facilitating servicing of the knitting head.

The needle cylinder 21 and the dial are driven by a conventional ring gear 31 connected to the main drive shaft 32 through suitable gearing including a clutch (not shown) for shifting between unidirectional rotation and reciprocatory rotation respectively. The main drive shaft 32 is driven from a drive motor in the lower portion of the frame 20 through suitable driving connections 33.

The sequential operations of the knitting instrumentalities of the knitting machine are controlled by pattern mechanism including in the present instance, three pattern control drums, a front drum 41, a rear drum 42, and an auxiliary drum 43, all of which are selectively indexed in timed relation to the rotation of the needle cylinder under the control of a conventional pattern chain or other master pattern control mechanism. During the course of the knitting of a complete stocking blank, the needles 45 are individually controlled by a needle cam box 46 including conventional cams operable on the butts 145 of the needles, and by lifter jacks 48 and selector jacks 47 mounted in the cylinder 21 underlying the needles 45 and operable to selectively elevate the needles. Below the needle cam box 46 is disposed a cam bed 152 having a cam track 130 for the butts 148, the lifter jacks 48, the track 130 having a pair of radially displaceable slides 131, 132 and 137, and a plurality of fixed lifter cams 133, 134, 135, and 136. The selector jacks, in turn, are actuated by actuators in the form of selector slides, in the present instance arranged in three arrays 51, 52, and 53 (see FIG. 4) cooperating with fixed cams 155, 155, and 157 respectively. The slides 51 are controlled from a right hand pattern selection drum 61 and the slides 52 are controlled from a left hand pattern selection drum (not shown). The slides 53 which constitute an array of six slides, are controlled separately by one of the control drums, in the present instance, the front drum 41. In like manner, the lowermost six slides of the array 51 are controlled from the front drum 41 and the lowermost six slides of the array 52 are controlled from the rear drum 42. An individual draw-down slide 54 adjacent the array 51 and a companion elevator slide 54a in advance of the array 52 are controlled from the rear drum 42.

The slides 51 and 52 are arranged in sets of any desired number each, for example six, and each set may be inactivated independently of its associated pattern selection drum by control mechanism operated from the front drum 41, for example by cams 119, followers 118, and push rods 115. The control mechanism for the array of slides 51, is designated generally 55, and the control mechanism for the array 52 is designated generally 56. In the drawings, the control mechanisms 55 and 56 are protected by cover members 57 and 58.

FIG. illustrates a typical butt arrangement for the needles and jacks for a knitting system made in accordance with the present invention. Reading from the top of the figure, the first row indicates the needle butts 145 which cooperate with the needle cams in the cam box 46. The second row indicates the butts 148 of the lifter jacks 48 which cooperate wit-h lifter cam track 130 in the bed 152 intermediate the needle cam box 46 and the selector jack slides 51 and 52. In each of these rows in FIG. 5, each line indicates an individual butt, the length of the line indicating the length of the butt. As shown, the needle butts 145 are of varying lengths, including long, intermediate, and short butts arranged in groups about the circumference of the cylinder. The lifter jack butts 148 include long, intermediate, and short butts, each alternate butt being a short butt and the long and intermediate intervening butts being arranged in groups comprising one half of the circumferential length of the cylinder.

The remainder of FIG. 5 indicates a typical butt arrangernent on the selector jacks 47. Adjacent the upper end of each of the selector jacks 47 is an upper guide butt 151 which rides on the underedge of the bed 152 and may selectively control needles through the medium of the slide 54a when the latter is displaced into active position. The butts 151 comprise a full complement arranged in two sectors, one sector comprising long butts designated L and the other sector comprising short butts designated S. In the present instance, the short butts 151-S embrace one half of the cylinder and underlie the long lifter butts 148 and the long butts 151L embrace the remaining half of the cylinder and underlie the intermediate lifter butts 148. It should be noted that with radially slidablc cams, such as the slide 54a, the slide is advanced stepwise into active position. The first step of the advance occurs during the time when the sector of short butts is advancing past the slide, and the final step occurs during the period when the sector of long butts is advancing past and upwardly upon the slide so that when the short butts again pass the slides, the slide is fully inserted to elevate the short butts.

Spaced below the butts 151 on the jacks 47 are drive butts 154. As shown in FIG. 5, the drive butts 154 comprise a full complement of uniform length to cooperate with the fixed cams 155, 156, and 157 immediately beyond the selector slides 51, 52, and 53. The butts 154 are engaged with the cams 155, 156, or 157 by displacement of the jacks 47 through the medium of one or more of the selector slides 51, 52, or 53.

Below the drive butts 154 are selector butts arranged in three groups 161, 162, and 163. Each of the groups 161 and 162 comprise butts at thirty (30) patterning levels, the presence of a butt at a particular level being indicated by an X, and the absence of a butt being indicated by a blank. The group 163 comprises butts at six (6) other levels and the length of the butts are indicated in FIG. 5 by the designations L and S the absence of a butt being indicated by a blank. The group 161 cooper ates with the upper thirty slides and the group 162 cooperates with the next thirty slides of the selector slide arrays 51 and 52. The butts in the groups 161 and 162 are arranged in sets corresponding in number to the number of slides in the slide sets mentioned above. For example, in the illustrated jack butt arrangement the patterning butts are arranged in sets of six butt levels each. The group 163 cooperates with the lower six (6) slides of the arrays 51 and 52 and also the entire array 53.

Below the group 163 and adjacent the bottom of the jack is a lower guide butt 164 which rides on the upper edge of the lower bed 165 and may be selectively engaged by the slide 54. It should be noted that the butts 164 comprise a full complement arranged in sectors of long and short butts which are opposite to the sectors of long and short butts of the butts 151.

The slides cooperating with the butts 151, 163, and 164 are inserted into action stepwise as noted above so that if desired, there may be a full complement of butts arranged about the full circumference of the cylinder. The selector slides cooperating with the butts 161 and 162 at the patterning levels, on the other hand, are not displaced into their inserted position stepwise, but are displaced betwecn their fully inserted and fully retracted position in one movement. In order to enable such move. ment without damaging the butts on the selector jacks, the butts in the groups 161 and 162 are confined to limited circumferential sectors of the cylinder. In the present instance, there are four hundred and one (401) selector jacks 46 disposed about the circumference of the cylinder and the group of butts 161 embraces one hundred and thirty-nine (139) of these jacks. The group 162, on the other hand, embraces the remaining two hundred and sixty-two (262) jacks. In this way, the slides for the groups 161 may be displaced freely without damage to the butts during that portion of the cycle when the 262 jacks are passing these slides. The slides for the butts 162 on the other hand, are displaced in that period when the 139 jacks are passing those butts. The cams and slides which operate on the butts 145, 148, 151, 163, and 164 are all controlled from the pattern control drums 41, 42, and 43 or other pattern control devices whereas the selector slides which operate on the butts 161 and 162 are controlled from the pattern selector drums.

In accordance with the invention, the cams and slides operable on the butts of the lifter jacks 48 and the selector jacks 47 afford a high degree of selectivity as to the needle position independently of the needle cams. As shown, the slides 51 and the cooperating cam 155 are operable to elevate the selector jacks 47 in two steps, the slides 51 elevating the jacks 47 a small distance from its normal position to an intermediate position sufiicient to engage the large butt 154 on the cam 155, the drive cam 155 raising the jack the remaining distance to its fully elevated position. By this arrangement, the rise of the slides 51 may be relatively small, thereby permitting close spacing of the relatively small selector butts 161, 162, and 163 without danger of the butts interfering with adjacent slides. Elevation of the selector jack 47 by the cam 155 is only sufiicient to displace the lifter jack 48 associated with that selector jack 47 from its normal position to an intermediate position wherein its heavy butt 148 is engaged on the upper surface of the cam 133 which, in turn, elevates the lifter jack 48 to an elevated position and lifts the associated needle 45 upwardly to a float level indicated at 45 The needles associated with the remaining jacks which are not engaged by slides in the array 51 may be raised to a low clear height shown at 45-c in FIG. 4 by the conventional clearing cam in the needle cam box 46 if such cam is placed in action. If such cam is not placed in action, the needles pass through the station 72 either at the tuck level indicated at 45-a or the welt level 45-w, depending on the position of the needle cams in the box 46 in advance of the station. During the period when the cam 133 raises the selected lifter jacks 48, the elevated selector jacks 47 are lowered to their normal position by the underedge of the bed 152.

If it is desired to repeat at the secondstation 73, the selection previously made by the slides 51, the slides 54 and 54a are displaced into the path of the guide butts 164 and 151. The slide 54 operates on the lower guide butts 164 of the jacks which were not elevated by the slides 51 and displaces the non-selected selector jacks 47 downwardly from their normal position into a repeater track 54b in the lower bed 165. The previously selected jacks are not returned to their normal level until after the slide 54 has displaced its jacks, and the previously selected jacks continue to ride with their upper guide butt 151 on the undersurface of the upper bed 152 and are displaced upward-1y by the slide 54a, the slide 131 in the lifter cam track 130 being withdrawn out of the path of the butts 148. Elevation of the selector jacks 47 by the slide 54a displaces the heavy butts of the associated lifter jacks 48 onto the cam 134 which raises the associated needles to a reinforce level shown at 45-g corresponding substantially to the float level 45- at the previous station. Thus, the same needles which were raised at the first station repeat their elevation at the second station. The remaining needles are normally raised to the tuck level 45-a by a cam in the needle cam box 46. In the period when the lifter jacks are raised by the cam 134, the selector jacks 47 are all returned to their normal level by engagement of the upper guide butt 151 with the lower edge of the bed 152, or engagement of the lower guide butt 154 with the upper edge of the lower bed 165 in the terminal portion of the repeater track 541). Thus, the selector jacks are free to pass the selector slides 52 at their normal level, and the lifter jacks which were elevated by the cam 134, are then lowered by the cam track 130 to their normal level.

If it is desired to make an independent selection of the needles at the auxiliary feed station 73, the repeater slides 54 and 54a are inactivated, thereby maintaining the selector jacks at their normal level throughout their travel from the feed station 72 to the slide array 52. The selection for the station 73 may be effected similarly to the selection for the station 72; the slides 52, the cam 156, and the lifter cam 1*35 elevating the jacks and needles selected by the butts on the selector jack 47 in three steps. In the present instance, the cam 1'35 elevates the lifter jacks a distance to displace the needles to a low clear height illustrated at 45b corresponding substantially to the clearing level shown at 45c. The needles not selected by the jacks 47 pass through the station 73 either at the tuck level 45-a or welt level 45-w, depending on the cam setup in the needle cam box 46.

The array of slides 53 operates to select needles for an elevated inactive level, such as when forming a split foot, toe, and heel and the like. The array 53 comprises six (6) slides operative on the butts in the group 163 to elevate the selected jacks 47 onto the cam 157, which in turn, elevates the jack only the distance needed to displace the heavy butt 148 of lifter jack 48 onto the cam 136. The cam 136 raises the lifter jacks a distance to position the needles associated therewith to an elevated or inactive level indicated at 45-h. The needles, when selected by the slides 53, provide various types or forms of heel and toe, depending on the slides activated, the conventional narrowing and widening being performed by the usual down-picks and up-picks (not shown) in the needle cam box 46.

The arrangement of the three arrays of slides 51 and '52 and 53 operable on the selector jacks 47, provides wide pattern selectivity as well as providing means for producing several types of stockings with the same jack setup in the needle cylinder and in the pattern drums. Thus, by the present invention, it is possible to change from one pattern to another or to change from one stocking type to another by simply changing actuating cams on the various pattern control drums 41, 42, and 43. When selecting needles for elevation by means of the slide arrays 51, 52, and 53, the lifter jack slides 131 and 132 are withdrawn to confine the control of thr lifter jacks 48 to their associated selector jacks 47.

.During selected portions of the knitting of a ladys stocking, for example during makeup and transfer, it is desirable to elevate every alternate needle at one or both of the knitting stations. In accordance with the invention, the alternate selection of the needle is performed by the lifter jacks 4 8. To this end, as pointed out above, the lifter jacks are provided with butts of differing lengths, every alternate butt being a short butt. Thus, when the slides 131 and 132 are displaced into active position to intercept the long and the intermediate butts of the lifter jacks, the short butt jacks follow the normal path and do not rise whereas the remaining jacks are elevated onto the cams 1'34 and 137. The cam 134, as pointed out previously, raises the jacks to displace the needles 45 to the reinforce level 45-g. The cam 137 raises the lifter jacks 48 a distance to displace the needles to the float level 45- which substantially corresponds to the reinforce level 45-g. Thus, the selection of alternate needles is accomplished independently of the selector jacks 47 allording full utilization of the butt levels on the selector jacks for the desired pattern and hosiery-type selection. The selection or" the pattern or hosiery type is accomplished by arranging the slides and selector butts in sets and utilizing the pattern control mechanisms 55 and 56 in conjunction with the pattern control drums 41, 42, and 43, as set forth more fully in our copending application, Pattern Mechanism for Circular Knitting Machines, Ser. No. 363,026, filed concurrently herewith.

-It should be noted that both the selector jacks 47 and the lifter jacks 48 are returned to their normal lowered level promptly after they have been elevated and have performed their desired function. Although for the purposes of illustration, the needle butts 145 in FIG. 4 have been shown at the wel level in advance of each feed station, it is rare when these butts are disposed at that level, the normal level being the tuck level. Thus, the present invention imparts the greatest load on the needle butts 145 and the lifter jack butts 148 which are of relatively heavy construction and design to withstand the load required to displace the needles which have yarn and fabric engaged thereon. The relatively small selector butts in the groups 151, 162, and 163 are cammed by the slides $1, 52, and 53 only a relatively small distance suffic-ient to engage the drive butt 154 on the associated cam 155, 56, or 157. This small displacement of the selector jack 47 is resisted very little by the lifter jack, and thus in the absence of loading, the butts in the groups 161, 152, and 163 are subject only to minimum wear and are not likely to be damaged in normal operation. The longer drive butts 154 are subjected only to the load of the lifter jack necessary to displace the lifter butt 148 onto one of the cams. However, since the needles are normally not at the welt level, the load imposed on the drive butt 154 is only that load which is occasioned by displacement of the lifter jack. The major load on the butts of the jacks is borne by the lifter jack butt 148 which is relatively heavy and rides on a fixed cam during that portion of its elevation when the needles offer their greatest resistance to vertical elevation. Since the butt arrangement on the lifter jacks is standard, regardless of the patterns which are desired to be set up in the knitting machine, the lifter butts may be made of relatively heavy and durable materials and may be set into the knitting machine with proper tolerances at the factory. T o be sure, the needle butts are subjected to loads similar to the loads borne by the lifter jack butts, but it should be noted that the needles are readily accessible for replacement from the top of the cylinder, particularly in view of the novel arrangement of the knitting head discussed above.

When it is desired to lay in an elastic or other yarn, for example in the welt or shadow welt, the slide 132 may be inserted and the cam 137 may be withdrawn. The slide 132 raises the alternate lifter jacks 48 a distance suflicient to elevate the needles to the tuck height, shown at 45-a, at which height the alternate needles may take an elastic yarn fed thereto at that point without clearing the previous loops. At the next feed station 72, the elastic yarn is cleared from the needle hooks and latches with the previous loops, so that it is laid into the knitted fabric without being formed into knitted loops.

Thus, the present invention provides a knitting system for a circular knitting machine having wide versatility for producing various patterns through the control of the needles. The butts on the needles and jacks are arranged and utilized so as to provide the greatest load on the butts which are capable of accommodating the load. The elevation of the needles is accurately controlled by the lifter jacks which in most cases are displaced to their ultimate elevated levels by stationary fixed cams, thereby avoiding the clearance required for sliding tolerances in movable cams. This knitting system provides a highly accurate control of the needles, at the same time providing means for producing all of the normal stitch forms.

While a particular embodiment of the present invention has been herein illustrated and described, it is not intended to limit the invention to such disclosure, but changes and modifications may be made therein and thereto within the scope of the following claims.

We claim: Y

1. A knitting system for a circular knitting machine having a needle cylinder with needles, lifter jacks, and selector jacks mounted therein for independent elevation therein, a cam system surrounding said cylinder for engaging the butts of said needles, lifter jacks, and selector jacks, and means to rotate said cylinder relative to said cam system, said cam system including a needle cam box having cams operable on the needle butts, a litter cam track operable on the butts of said lifter jacks, and an array of radially displaceable selector slides operable on pattern butts of the selector jacks, said selector slides and selector jack pattern butts being disposed at a plurality of levels, each selector slide, when displaced into the path of the butts, operable to engage under the butt at the corresponding level on any selector jack and to elevate the selector jack from its normal position, a predetermined distance to an intermediate position, said selector jacks having a drive butt thereon, and a fixed drive cam disposed out of the path of the drive butts on the jacks in the normal position and in the path of the drive butts on the jacks in the intermediate position, said drive cam operable to engage under said intermediately positioned drive butts and elevate the selector jacks from said intermediate position to an elevated position, said elevation of the selector jack elevating the associated lifter jack from a normal position to an intermediate position, the'lifter cam track including a lift cam disposed out of the path of the butts of the lifter jacks in the normal position and in the path of the butts of the lifter jacks in the intermediate position, said lifter cam operable to engage under said intermediately positioned lifter jack butts and elevate the lifter jacks to an elevated position, said elevation of the lifter jack operable to lift the associated needle to a selected position in said needle cam box.

2. A knitting system according to claim 1 wherein said selector jack pattern butts are relatively small and arranged at closely spaced levels, said drive butts are longer than said pattern butts, and said lifter jack butts are heavier than said drive butts.

3. A knitting system according to claim 1 including a second array of radially displaceable selector slides and a second drive cam operable to displace selected selector jacks to the same intermediate and elevated positions respectively, and second lift cam operable to lift the lifter jacks associated with said selector jacks elevated by said second array to lift the associated needles to an elevated position in said needle cam box.

4. A knitting system according to claim 3 wherein the rise of said second lift cam is less than the rise of the first lift cam whereby said elevated position of said needles is lower than said selected position.

5. A knitting system according to claim 4 including a third array of radially displaceable selector slides and a third drive cam operable to displace selected selector jacks to the same intermediate and elevated positions respec tively, and a third lift cam operable to lift the lifter jacks associated with the selector jacks displaced by said third array to lift the associated needles to a raised position in said needle cam box above both the elevated position and the selected position of said needles.

6. A knitting system according to claim 1 wherein said lifter jacks have butts of varying length, and including slides in said lifter jack cam track operable to be displaced radially into the path of the butts on the lifter jacks in the normal position, said displaced slides operable to engage under long butts of the jacks and elevate the long-batted jacks to an intermediate position for subsequent elevation by a lift cam in said track to lift the associated needles to an elevated position in said needle cam box.

7. A knitting system according to claim 6 including multiple feed stations spaced apart about the cam system and including one of said lifter cam track slides in advance of each of a plurality of said feed stations.

8. A knitting system according to claim 1 including at least two feed stations spaced apart about the cam system, said array of selector slides being disposed in ad vance of one of said stations, said selector jack having at least two levels of a full complement of butts, a first repeat slide following said array operable to be displaced into the path of the butts at one of said two levels on the jacks remaining in their normal position, said slide, when displaced, engaging over said butts and lowering said jacks to a lower level in a repeater track, means to return jacks elevated by said array back to said normal position beyond said first repeat slide, a second repeat slide beyond said return means and in advance of said second station operable to be displaced into the path of the butts at one of said two levels on the jacks returned to their normal position, said second slide, when displaced, engaging under said butts and elevating the selector jacks to the aforesaid elevated position, said elevation of the selector jack elevating the associated lifter jack from the normal position to said intermediate position, the lifter cam track including a second lift cam disposed in advance of said second feed stat-ion and in the path of the butts of the lifter jacks elevated by the selector jacks engaging said second repeat slide, said second lift cam operable to elevate the lifter jacks from the intermediate position to an elevated position, said elevation of lifter jack operable to lift the needle to a position corresponding substantially to said selected position at said first feed station.

9. A knitting system according to claim 8 including means to return said lowered jacks to their normal position at the end of the repeater track and in advance of the second feed station, and means to return the remaining jacks to the normal position beyond said second slide and in advance of the second feed station.

10. A knitting system according to claim 1 wherein said lift cam is fixed in position.

11. A knitting system according to claim 1 including means to return each elevated jack to its normal position promptly after completion of its elevation.

References Cited by the Examiner UNITED STATES PATENTS 2,040,021 5/1936 Paquette 66--28 2,382,750 8/1945 St. Pierre et al. 66-8 2,409,306 10/1946 Page et al., 66125 2,527,688 10/1950 St. Pierre 662'8 2,755,645 7/1956 Deans et 'al. 6650 3,224,226 12/1965 Luchi 66-5O 3,246,489 4/1966 Bella 66-145 X MERVIN STEIN, Primary Examiner.

R. FELDBAUM, Assistant Examiner. 

1. A KNITTING SYSTEM FOR A CIRCULAR KNITTING MACHINE HAVING A NEEDLE CYLINDER WITH NEEDLES, LIFTER JACKS, AND SELECTOR JACKS MOUNTED THEREIN FOR INDEPENDENT ELEVATION THEREIN, A CAM SYSTEM SURROUNDING SAID CYLINDER FOR ENGAGING THE BUTTS OF SAID NEEDLES, LIFTER JACKS, AND SELECTOR JACKS, AND MEANS TO ROTATE SAID CYLINDER RELATIVE TO SAID CAM SYSTEM, SAID CAM SYSTEM INCLUDING A NEEDLE CAM BOX HAVING CAMS OPERABLE ON THE NEEDLE BUTTS, A LIFTER CAM TRACK OPERABLE ON THE BUTTS OF SAID LIFTER JACKS, AND AN ARRAY OF RADIALLY DISPLACEABLE SELECTOR SLIDES OPERABLE ON PATTERN BUTTS OF THE SELECTOR JACKS, SAID SELECTOR SLIDES AND SELECTOR JACK PATTERN BUTTS BEING DISPOSED AT A PLURALITY OF LEVELS, EACH SELECTOR SLIDE, WHEN DISPLACED INTO THE PATH OF THE BUTTS, OPERABLE TO ENGAGE UNDER THE BUTT AT THE CORRESPONDING LEVEL ON ANY SELECTOR JACK AND TO ELEVATE THE SELECTOR JACK FROM ITS NORMAL POSITION, A PREDETERMINED DISTANCE TO AN INTERMEDIATE POSITION, SAID SELECTOR JACKS HAVING A DRIVE BUTT THEREON, AND A FIXED DRIVE CAM DISPOSED OUT OF THE PATH OF THE DRIVE BUTTS ON THE JACKS IN THE NORMAL POSITION AND IN THE PATH OF THE DRIVE BUTTS ON THE JACKS IN THE INTERMEDIATE POSITION, SAID DRIVE CAM OPERABLE TO ENGAGE UNDER SAID INTERMEDIATELY POSITIONED DRIVE BUTTS AND ELEVATE THE SELECTOR JACKS FROM SAID INTERMEDIATE POSITION TO AN ELEVATED POSITION, SAID ELEVATION OF THE SELECTOR JACK ELEVATING THE ASSOCIATED LIFTER JACK FROM A NORMAL POSITION TO AN INTERMEDIATE POSITION, THE LIFTER CAM TRACK INCLUDING A LIFT CAM DISPOSED OUT OF THE PATH OF THE BUTTS OF THE LIFTER JACKS IN THE NORMAL POSITION AND IN THE PATH OF THE BUTTS OF THE LIFTER JACKS IN THE INTERMEDIATE POSITION, SAID LIFTER CAM OPERABLE TO ENGAGE UNDER SAID INTERMEDIATELY POSITIONED LIFTER JACK BUTTS AND ELEVATE THE LIFTER JACKS TO AN ELEVATED POSITION, SAID ELEVATION OF THE LIFTER JACK OPERABLE TO LIFT THE ASSOCIATED NEEDLE TO A SELECTED POSITION IN SAID NEEDLE CAM BOX. 